Rotary pulverizer



Nov. l, 1927.

w. H. HARTMAN ROTARY PULVERIZER 2 Sheets-Sheet -1 Filed Jan. 12. 1927 i. l l

W. H. HARTMAN ROTARY PULVEHI ZER Filed Janl2. 1927 2 Sheets-Sheet 2 Quoi new Patented Nov. 1, 1927.

UNITED STATES 1,647,730 PATENT OFFICE.

WILLIAM H. HARTMAN, OFOANTON, OHIO, ASSIGNOR'TO THE BONNOT COMPANY, 0F

` CANTON, OHIO, A. CORPORATION OF OHIO.

ROTARY- PULVERIZER.

Application filed January 12, 1927. Serial No. 160,629.

This invention relates to rotary pulverizers, of the hammer type, for crushing or grinding hard material, where the grinding is not necessarily very fine; and more particularly to means for removing uncrushable materials from the mill to prevent damage to the working parts thereof.

In the crushing of various materials such as mills of this general'character are adapted to handle, various uncrushable or refractory objects frequently pass into the mill, with the material to be crushed, and these hard substances frequently cause considerable daliage to the rapidly moving parts of the m1 Attempts have been made heretofore to remove these hard substances from the mill by providing a normally open trap communicating with the cylinder and adapted to re- 90 ceive uncrushable substances. Such devices,

however, are objectionable as the normally open trap receives not only the uncrushable objects but a considerable portion of the crushed material, thus necessitating frequent cleaning of the trap. Attempts'have also been made to remove uncrushable objects from the mill by providing a spring pressed door in one side of the cylinder, opening to the exterior, the hard objects striking the door with sufficient force to open the same and pass there'- through. Such devices, however, are not practical as the material being ejected .from the cylinder is thrown out of the mill and into the room where the mill is located.

The object of the invention is to provide a mill of this type with a trap communieating with one side of the cylinder, a normally closed door being provided between the cylinder and trap and arranged to be opened by the weight of a heavy object striking the same, permitting the object to pass into the trap and the door being automatically closed of its own weight, and so arranged that light material striking against the door will not open the same; a breaker block being located within the cylinder adjacent to the door and in such positionthat heavy material thrown against the block, by the hammers of the mill, will glance from the block and strike the door. The trap may also be provided with a perforate bottom to permit any fine material which may pass into the same to be sifted through the bottom, thus preventing undue clogging of the trap.

A trap door may be provided in the upper portion of the trap, to permit a Workman to insert his hand, to remove the hard objects from the trap, and in so doing the workman will be protected against injury .by the door between the trap and cylinder, as should any hard object strike this door, during the time the workman is cleaning the trap, the door will prevent the object from striking the workman.

An embodiment of the invention is illustrated in the accompanying drawings, in which Figure 1 is a vertical sectional view through a swing hammer mill provided with the improved refractory trap, and

Fig. 2, an enlarged sectional view of the trap.

` Similar numerals of reference indicate corresponding parts throughout the drawings.

The mill may comprise a cylinder or casing indicated generally at 1 having the concave grate 2 in its lower side. A rotor is mounted within the cylinder upon a rotary shaft 3, the rotor being in the form of disks 4 keyed upon the shaft, as at 5 and provided with several series of apertures 6, 6a and 6b differentially spaced from the center.

Hammers 7 may be pivotally mounted upon rods 8,1ocated through any desired series of the apertures in the disks, depending upon the amount of wear to which the hammers have been subjected, as in standard practice.

The rotor is arranged to be rotated at a considerable speed in the direction of the arrow shown on Fig. 1.

The material to be crushed or ground is fed through the feed opening 9 into the cylinder. A breaker plate is located in the wall of the cylinder adjacent to the feedl opening and may comprise the casting 10 hinged at its upper end, adjacent to the feed opening, as at 11 and provided with the wear plates 12 upon its inner face, near the upper portion thereof, and with the breaker block 13 at its lower portion.

This breaker plate is arranged to be adjustably, resiliently mounted by means of the coil spring 14, one end of which is located in a socket 15, in the casting 10, the

other end thereof being located 'around the shouldered head 16 of the adjusting screw 17.

A trap 18 is located at one side of the cylinder, preferably upon the opposite side to the feed opening 9, as illustrated in Fig. 2, and a door 19, pivoted at its upper end as at 20, is arranged to normally close the trap from communication with the cylinder.

The lower end of the door may be provided with the angular lip 19a arranged to contact with the angular fiange 21 and to be held in contact therewith by the weight of the door itself, or if desired, a weight arm 22 may be provided upon the door.

A breaker. block 23 is provided in the cylinder adjacent to the hinged upper end of the door and having .the angular end 24: so located that refractory articles bein thrown up against the same by the action o the hammers, will be deflected against the door, the impact of the blow opening the door suiliciently to deposit said refractory article within the trap 18, the door immediat'ely returning to the closed position by reason of its weight.

In order to provide for ridding the trap of any line material which may be thrown into the same, a perforate bottom 25 is provided in the trap.

For the purpose of removing the refractory material from the trap a hand opening 26 is provided in the upper wall thereof and d arranged to be normally closed as by the door 27 hinged as at 28 and provided with a handle 29.

In the operation of the mill, the material to be crushed is fed through the opening 9 and falling or being thrown upon the breaker block 13, by the action of the hammers, the larger port-ions of the material may y be broken. The material is carried around the cylinder and subjected to the action of the hammers until reduced to a condition fine enough to permit the same to pass downward through the grate 2. Refractory objects which may accidentally find their way into the cylinder will be ejected by glancing from the breaker block 23 against the door 19, being deposited in the trap as above described, thus `preventing injury to the mill which might be caused by such refractory objects being continuously thrown around within the same.

In the event a workman opens the trap door 20 to remove refractory objects from .the trap, he can do so without danger of injury as should the mill be running and other refractory objects ejected from the cylinder, into the trap, during this time, the door 19 will prevent such objects from striking his hand or otherwise injuring him.

`From the above it will be seen that the improved mill is provided with a trap normally closed from the cylinder while at the same time permitting free access thereto of any refractory objects which should be ejected from the mill; while at the same time refractor objects ejected from the mill will be trappe within the trap 18 and not thrown promiscuously about the room in which the mill is located.

It will also be seen that by having the trap normally closed, no considerable amount of fine vmaterial will be thrown into the trap and thus unnecessarilv clog the same and any small portion of fine material which is received into the trap will pass out through the perforate bottom thereof.

It will also be seen that a novel means of resiliently adjusting the breaker plate is provided whereby .any desired adjustment of the breaker plate may be obtained by the operation of a single adjusting screw.

I claim:

1. In a crushing mill, the combination of rotating hammers, a cylinder in which the hammers are located, said cylinder having an inlet openin and a grinding surface having passages or the discharge of ground material, a trap external to the wall of the cylinder. a door normally shutting off communication between the cylinder and trap and arranged to open only when a heavy 0bjectis thrown against it, and a breaker block in the cylinder adjacent to the door and arranged to deflect heavy objects against the oor.

2. In a crushing mill, the combination of rotating hammers, a cylinder in which the hammers are located, said cylinder having an inlet opening and a grinding surface having passages for the discharge of ground material, a trap external to the wall of the cylinder, a door normally shutting olf communication between the cylinder and trap and arranged to open only when a heavy ob-y v ject is thrown against it, a breaker block in the cylinder adjacent to the door and arranged to deiect heavy objects against the door, and a trap door in the top of said trap.

3. In a crushing mill, the combination of rotating hammers, a cylinder in which the hammers are located, said cylinder having an inlet opening and a grinding surface having passages for the discharge of ground material and a breaker plate in the cylinder pivoted at its upper end adjacent to the inlet opening, and resilient means for adjusting 'the lower end of the breaker plate.

4. In a crushing mill, the combination of rotating hammers, a cylinder'in which the hammers are located, said cylinder having an inlet opening and a grinding surface having passages for the discharge of ground Inaterial and a breaker plate in the cylinder pivoted at its upper end adjacent to the inlet opening. and a resilient adjustable mounting for the lower end of the breaker plate.

5. In a crushing mill, the combination of rotating hammers, a cylinder in which the wears@ hammers are locate7 sairl cyliner having' an inlet opening and a grinding surtacehaving passages for the discharge of grouncl material and a lorealrer plate in the cylinder pivoted at its upper end adjacent to the inlet opening, an adjusting screw for adjusting the lower endo the breaker plate and a spring interposed between the adjusting screw and breaker plate.

6. In a crushing mill, the Combination of rotating hammers, a cylinder in which the hammers are located, said` cylinder having an inlet opening and a grinding surface having passages for the discharge of ground material, a trap external to the Wall of the e llwhen a heavy object is thrown against the door, and a trap door in said trap, the lirst named door and trap door being so located that articles passing through the first named door Will be prevented from striking the trap door. A

kIn testimony that I claim the above I have hereunto subscribed my name.

lWILLIAM H. HARTMAN. 

